Along Came a Blackbird
by StoneWingedAngel
Summary: Sherlock and John are lost; John doesn't know where they are, or how they got there. He does, however, know that it's absolutely impossible to be found by a man who, even if he existed at all, should have died a very, very long time ago.
1. Chapter 1

**Warnings: Pre-Reichenbach.**

**Written for a prompt from the lovely martinsbutt on tumblr who requested a Sherlock/Merlin crossover after an experiment gone wrong.**

* * *

"We're lost."

"No, we're not," Sherlock said firmly. His mouth was a thin line; John could see wrinkles forming at the edges of his lips. "We just need to-"

John came to a halt, putting his hands on his hips and resolving not to go another step; Sherlock could whine as much as he liked, but John wouldn't be listening, and neither would anyone else – there was no-one in the woods apart from themselves and the occasional bird. "Face it, Sherlock, or it'll come back to bite you. We're lost."

"You're not helping, John!" Sherlock stopped walking and turned around with a flourish that made John want to smirk; there was mud on his forehead, and it rather ruined the effect. "If we're lost, then we need to keep going."

"There's no 'if' about. And what we _need _to do is listen for water, and find shelter before it gets dark, or we have a good chance of freezing to death." He sighed, and scrubbed a hand over his face; there was soot engrained in his palm lines and it left his eyebrows feeling gritty. "It would help if we knew which part of the country we were in."

Sherlock was frowning. "I would say towards the south; still in the UK, if the climate and our body clocks are anything to go by. Only…"

"Only?"

"There's too much woodland. Too dense. There's been no woodland this dense in Britain for centuries."

John swallowed. His throat was dry and raw. "Do you remember anything yet?"

Sherlock shook his head. "Photographs – purple smoke – here. You?"

John closed his eyes for a moment, thinking. Sherlock had been developing old picture film, for a case, surrounded by test-tubes and the remains of experiments. He remembered thinking that Sherlock should really organise himself a little better; he hadn't been paying attention. His arm had brushed Sherlock's, and something had been knocked over. Purple smoke. Fizzing. The smell off…he couldn't quite fathom the smell. Almost like burned bananas.

"John?"

"No." He put a hand to his head, wishing that he felt something other than dehydrated; it might have presented him with a clue as to exactly what they had been given to make them sleep for so long that they could be moved whole miles and left in the middle of nowhere. "You're sure it wasn't the smoke?"

Sherlock shook his head. He was pale and sweaty, and his voice kept cracking. "It shouldn't have made us pass out. And that doesn't explain-"

"-here."

"Yes. Here."

"Alright." John let his arms fall to his side. "We need water, or I'm going to fall over. There's no point trying to get out yet; trust me."

Eventually, Sherlock nodded. "Lead on, soldier."

John rolled his eyes. "We move strategically, and keep together. Listen for running water."

"Easier said than done."

"You'd be surprised," John murmured. The woods were very quiet. He supposed that was a good thing, but it also worried him. It meant that they weren't well-frequented; in the two or three hours he and Sherlock had been trying to find their way, they hadn't encountered a single footpath, or the remains of a fire. Even the trees were free of graffiti. It was unnerving.

They covered ground slowly, brown leaves crunching underfoot. Already, it was getting dark. Neither of them talked about how they could have got here – about _who_ could have put them here. Whoever it was did not have their best interests at heart. John had seen enough movies to imagine scenarios of the two of them being chased down by a maniac with wild dogs. Moriarty was out there, somewhere. John wouldn't put it past him.

It would be very easy to kill them here.

"John!"  
John jumped, and span around; Sherlock was standing with a hand cupped to his ear, raised on tiptoes. "What?" John hissed, heart thudding. "Is it water?"

Sherlock shook his head. "It's…someone."

"Someone?"

"Footsteps."

Perhaps it was the darkness, or perhaps it was the image of Sherlock being torn apart by dogs, but John didn't immediately begin shouting for help. "How many people?"

"One."

John swallowed. "Who goes this deep into the woods on their own?"

Sherlock lowered his hand and pressed his heels back into the leaves. They rustled, like breath. John could feel his guts squirming; his heartbeat had found its way to his stomach and was beating out a rhythm that was far too fast for his liking.

"How far away are they?" John murmured.

"About a minute. They'll see us sooner than that."

John swallowed, torn; on the one hand, he had spent the past four hours praying for someone to come and find them. On the other, he did not want to come face to face with whoever had put them here. Especially if it was Moriarty.

"Get up the tree," he said, pointing to the nearest. The branches were beginning to deaden in the winter chill – which was odd, because John was sure it had only just turned autumn – but even if they were a little sparse, he was relying on whoever it was not looking up. If they did, the trunk might be enough to conceal them.

Sherlock swung himself into the tree reasonably easily. John, having shorter legs and arms, struggled to get a firm hold, until Sherlock reached down a hand and helped him. For once, he didn't make a joke about John's height. Good job really; the last thing they needed now was to laugh. The leaves rustled as they scrabbled onto branches, John one below Sherlock, curling themselves awkwardly behind the thinning leaves.

The footsteps grew louder, crunching twigs and dead plants; whoever it was didn't seem to be bothered about making a noise. That was good, John told himself – it meant that they weren't suspicious. Even if they were looking for them, they couldn't think that they were nearby. Sherlock wobbled on the branch above him and righted himself with a small gasp. John looked down. The person came into view – a man, young enough to still be half a boy, and dark-haired, stooping every now and then and putting something in the dirty leather bag that hung at his side. He was strangely dressed – John thought he looked like something out of a Shakespeare production – but he didn't seem threatening, and he wasn't Moriarty.

Something touched his shoulder. John looked up as Sherlock withdrew his hand and pointed to the boy, inclining his head. John shrugged.

'He doesn't look dangerous' Sherlock mouthed. There were dead leaves and twigs in his hair.

The boy stooped again, stood, and scrubbed a hand over his forehead. Sherlock was right; he didn't look dangerous. Even if he was whoever had put them here, he didn't look like he'd be difficult to take in a fight.

John was about to put a foot on the branch below so that he could climb down when something stopped him; as the boy stretched, the hem of his tunic rode up. He was carrying a…was that a dagger? Sherlock saw it too and, instantly, his hand came down and gripped John by the collar. They waited, poised awkwardly in the branches, not breathing; John felt like he was drowning. He let air out through his nose, slowly.

The boy began to approach the bottom of the tree. John swallowed, wondering if he should drop down and attack whilst he still had the height advantage, wondering how much chance he had against a dagger, of all things, and if it would split his ankle open if he tried to land on top of it.

The boy reached for a mushroom, picked it, put it in his bag, and began to walk away again. He didn't even look up.

John allowed himself another gulp of air. His throat tickled, but he swallowed it; of all the stupid things to do, coughing would be one of them. The boy walked slowly. John willed him to go faster. The cough rose, until he risked taking one arm off the branch, leaned against the trunk and clamped a hand around his throat, massaging it. His heart was pulsing behind his ribs, making him dizzy. The cough died.

The blackbird came out of nowhere; it was a male, yellow-beaked and black-eyed, and it sat on a branch so close to him that John could see its chest puffing in and out as it settled itself down, and opened its beak.

John felt Sherlock wince. The blackbird burst into a song that seemed terrifyingly loud, like an alarm. John prayed the boy wouldn't notice, wouldn't care, would just keep on walking – it was a forest, there would be birds everywhere, he didn't _have _to notice it…

The boy stopped, walked a little way back toward the tree and looked into the branches, seeking out the bird. When he found it, he smiled. John forced himself to imagine that he was five years old again, playing musical statues with Harry, making himself to go completely still; their only hope was to stay still, behind the trunk, and pray. Sherlock's hand, still around his shoulder, was gripping so tightly that his nails were digging into John's skin. John resisted the urge to wince, biting his lip.

The blackbird took into the air with a final whistle, and the boy began to turn away again. John swallowed. Sherlock's fingers were grinding into his shoulder blade, and John removed the hand from his throat to tap them, let Sherlock know he was hurting. The leaves rustled, but the boy didn't look back. John's foot slipped on the branch as Sherlock's hand retracted, but he found his balance again easily enough, shifting onto the next one.

He didn't realise that part of the tree was dead until the branch snapped. Sherlock's hand snatched at his hair, John let out a yell that reverberated around his skull, a twig whipped against his face, and he fell.

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**Thanks for reading, feedback welcome! **

**To be continued. **


	2. Chapter 2

Merlin was dawdling on purpose. Mostly, it was to annoy Arthur – Merlin had been run all over the castle for the past week, cleaning up after the tournaments, and he was itching to make Arthur do something for himself. For once, he'd jumped at Gaius's request for herbs. The walk hadn't been long, and he wasn't expected back until evening. He'd even had time for a nap, and he felt refreshed. Discovering the oyster mushroom had been pure luck.

He was in a good mood. He wouldn't have conceived it on leaving the castle, but now, he was ready to go back. Darkness was beginning to fall, and the day was growing cold. He paused to listen to the blackbird – they reminded him of Arthur, with their puffed chests hiding their friendly natures and, he supposed, beginning to smile, their empty heads. The thought crossed his mind that his boots were beginning to wear at the heel, because he could feel the chill of the leaves on his sole, when something snapped. There was a loud yell, and then another. Merlin whipped around, scattering herbs. Casting the spell was instinctive; he had no choice in the matter. His palm burned, and the person who had just fallen from the branch was thrown backwards, crashing into a tree and collapsing with a thud and a yelp.

Merlin froze. He had no idea who he had just attacked; they were curled on the floor, wheezing, which meant they might not have seen his face. In which case, they might not be able to tell exactly who it was had performed sorcery. Merlin tensed, getting ready to run and pray they couldn't give an accurate account of events when there was a shout from the tree.

"John!"

With a slithering noise and a flash of white shirt, someone else landed. Merlin, unnerved, tried to flee and ended up stumbling and falling to his knees. By the time he began to stand, the second man had reached the first, seizing him by the shoulders and pulling him upright, still shouting.

"John, John!"

The first man groaned. There was blood trickling down his fair hair, and he had one arm wrapped around his chest, wheezing. "M'fine, Sherlock…"

Sherlock whipped his head towards Merlin, baring his teeth; he almost seemed to snarl. "What did you do?"

Merlin could feel his face stinging. These men were not dangerous; they were dirty and ragged and clinging to each other, and he could not kill them for that, not even to protect himself. "I-"

The man called John sagged against Sherlock's chest, closing his eyes. "John?" Sherlock murmured, shaking him. "Come on John, please…"

Merlin took his chance. He turned to try and run a second time. If he couldn't deny what he'd done, he could get as far away as possible and hope that they wouldn't seek him out. That they didn't live in Camelot. If he got back fast enough, he could deny ever being in that part of the forest.

"Wait! Wait!"

Merlin didn't wait. He kept running, slewing round a corner, stumbling, dropping his bag, carrying on. Footsteps sounded behind him as he dodged over a tree root and landed awkwardly, staggering sideways and crashing into a bush. As he began to plough through it a hand latched onto his neckerchief, bringing him to an abrupt, choking halt. Merlin gasped. The man called Sherlock yanked him out of the bush, back into the clearing where John was still on the ground, curled with his hands on his head, breathing heavily.

"What did you do to him?" Sherlock snarled pushing Merlin roughly to the ground.

Merlin didn't dare use magic again; if Sherlock was confused about what had happened, then it was possible that he hadn't recognised it the first time. "Nothing. It was just an accident, I swear."

John mumbled something. Sherlock dropped to his knees and lifted him up again, pushing his hair out of his face and checking the long cut on his temple. He was being very gentle for a man with such large hands, but his shoulders were trembling. John's eyes were half-closed and heavy, but the wheezing was beginning to ease. He didn't look badly hurt.

Merlin swallowed. "I have to go. I'm sorry. I have to go."  
"No!" Sherlock turned to him. "Don't – we're lost. If you leave, we won't be able to get out." Sherlock pressed a hand to his grimy forehead. He was sweating. "Please, just help him."

Merlin hesitated, began to say 'I can't', and cut himself off. Sherlock looked desperate, and with good reason; if he was telling the truth, if they were lost and Merlin left them, they could die. The forest was large, the rivers were scarce, and John was still bleeding. It didn't look serious, but if it was left for too long…

"I really must be an idiot," Merlin muttered, going to retrieve his bag before kneeling down beside them and tossing garlic and goose-grass aside until he found his water-skin. "Here."

Sherlock took it with an odd look and plucked the cork out. He sniffed, then offered it to John, who drank deeply. Sherlock didn't take any for himself until John had recovered himself a little and begun to sit by himself, one hand pressed to his temple and the other massaging his ribs.

"I have a request," Merlin said, taking the water-skin back and trying to look as if he knew what he was doing. "If I help you out of the woods, you can't tell anyone about this."

Sherlock didn't reply. He was looking at the water-skin very closely. Slowly, he raised a hand and sniffed his own fingers, then shook his head. "That's genuine."

Merlin looked down. "Genuine what?"

"Where are you from?"

"Camelot." Merlin narrowed his eyes. "Where are you from?"

"London," John muttered.

Sherlock shushed him. "A long way off. We don't know how we got here."

Merlin blinked. "Sorcery?"

"If you like. I was working with…potions. Something went wrong."

"Are you a sorcerer too?" Merlin murmured; the words were out before he could stop them and even if he wished he could reel them back, Sherlock didn't immediately start screaming. Perhaps things were different in where he came from; in London.

Sherlock shook his head. "No. I was-"

"What the hell are you on about?" John growled, dropping his hand from his head. His palm was smeared red, but the bleeding was beginning to slow. "Sorcery and bloody…Camelot…next you'll be on about King Arthur."

Merlin snapped to Arthur's defence, surprising himself a little; the man was a prat after all. Still, he was a normal prat, which these two definitely were not. "Arthur is not king yet, but he will be one day."

John's mouth opened in shock. Sherlock only looked thoughtful.

"I'm sorry?" John said. "Are you seriously talking about King Arthur?"

"Arthur Pendragon," Merlin replied, indignant. "_Prince _of Camelot."

John snorted. "I must have hit my head harder than I thought." He reached for Sherlock and hooked a hand into his shirt, keeping his eyes fixed on Merlin the whole time, as if he might bite. "Sherlock, take me home, it's not funny, whatever you're doing."

"I can't, John," Sherlock muttered. "It's real. Just believe it, for now."

"It's not _funny_!"

Sherlock turned to Merlin with a desperate look. "Please, help me get him somewhere safe. You're afraid of people finding out about your…"

"Sorcery."

Sherlock's nose curled, as if he didn't quite understand the word, but he nodded. "Yes. Can you imagine what they'll do to us? Look at the way we're dressed. How do you think we'd explain it?" Sherlock leaned forward, keeping John supported on his shoulder. "We aren't going to give you away. We can't. Take us somewhere safe. Please."

Merlin opened his mouth, then shut it again. He couldn't pretend that he understood what was going on, and he didn't think Sherlock understood it either. He was right about the way they were dressed, though; Merlin had never seen such material. It was too stiff, too fine at the seams, and John's shirt had far too many colours.

"Alright," Merlin murmured, pushing a hand through his hair. "I must be stupider than even Arthur thinks, but alright." He reached for his bag and pulled out the oyster mushroom he'd picked earlier. "Here, they're good raw."

As Sherlock tried to get John to eat – without success – Merlin tore off part of his tunic and soaked it with what was left of the water, making it into a square which he patted some of the more soothing herbs into. He bound the patch to John's head with a long strip torn from Sherlock's shirt; seeing as he would have to get them new clothes at some point, damaging it didn't really matter.

John looked drowsy and was still muttering to himself, but he stood easily enough when Sherlock supported him, and they began the journey back. The forest was growing darker and colder, and both Sherlock and John fell silent before they were halfway there. They both looked in shock. Sherlock had eaten a little of the mushroom, but was still horribly pale, and the blood on John's face and clothes didn't exactly make him look healthy. If Merlin had succeeded in running away from them…he didn't like to think about it.

For the first time since he'd seen them, Merlin felt that he was doing the right thing.

* * *

Getting to the castle under cover of darkness was less difficult than Merlin had expected, but he knew that taking them up to Gaius would be fraught with danger, and he didn't dare push his luck.

"This way," he murmured, tugging at Sherlock's sleeve and leading him down, into the winding and deserted passages beneath the castle. "No-one ever comes here; you'll be safe."

"You come here." Sherlock shifted his weight from one side to the other, causing John's head to flop. John let out a muffled curse. "How do you know we'll be safe?"

"I hid someone here before," Merlin said, trying not remember Freya, because now was not the time. He had to concentrate on getting them to a safe place, alive. "No-one found them."

"But they're dead."

Merlin jerked in his steps and whipped around. "How did you know that?"

"I didn't know. I saw." Sherlock waved a hand. "Just tell me the truth – will it be safe?"

"Yes." Merlin tipped his chin, trying to force himself to sound convinced. "It's the safest place here. I live with Gaius, but he has his patients, and I can't guarantee one of them wouldn't find you."

"Gaius is a doctor?"

"The court physician." Merlin felt his mouth twitch, despite himself. "The best."

"Are you going to tell him about us?"

Merlin bit his lip, thinking. It was true, Gaius might be able to help. On the other hand, the more he knew, the more likely he was to get into trouble. "Not unless I have to. The less he knows, the better." He motioned towards John. "If he gets any worse, I will."

"M'fine," John chipped in, raising a hand.

Sherlock smiled and put a hand on John's shoulder. "Of course you are."

"I'm a doctor, and I say I'm fine. Just need to sleep."

Merlin brought them to a halt in a small chamber full of shadows. Sherlock gently leaned John against the wall, helping him to sit. "I'll have to wake you up every two hours, you know."

John groaned. Sherlock let out a sigh. Merlin suddenly felt prickly, as if he didn't belong in whatever bizarre picture they were suddenly part of. "There's a privy down the hall – it's supposed to be for the guards, but no-one ever uses it down here; it's too out of the way. I'll get you some food and new clothes as soon as I can, but I might not be able to make it until the evening. Then maybe we can work out why you're here, and how to get you back."

"What's your name?"

The question came as a surprise; Merlin paused in the process of turning to go, legs bent awkwardly. "Merlin."

For a moment, Sherlock looked as if he was about to say something, and then he closed his mouth, put his hands under his chin and stared into the distance, as if Merlin had already left.

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**Thanks for reading, feedback welcome!**

**To be continued. **


	3. Chapter 3

John woke with his head feeling like it was stuffed with bees and his mouth stinging with acid. Gently, he rotated his shoulder, groaned, and sat up, propping himself against the wall.

"Sherlock?"

"John."

John turned to his left, ready to ask Sherlock what the hell was going on and tell him that it wasn't funny, but the words died on his lips when he actually saw Sherlock, pale-faced and with bags under his eyes John could have sat his coffee cup on. If he'd had a coffee cup. He really wanted coffee.

"God, have you been up all night?"

Sherlock inclined his head, but didn't look at John. His hands were steepled under his chin, and he was staring at the opposite wall. There was still mud behind his ears and blood under his nails. "I had to keep waking you. And I've been trying to understand what's happened to us."

John put a hand to his temple and touched it, wincing as the gash throbbed. At least someone had had the sense to cover it over. Who? "That boy, what's-his-name…"

"Merlin."

John felt something judder through his mind, like a bolt of lightning. "What?"

"No, you're not dreaming. Or hallucinating. You're not demonstrating any further signs of concussion, and I haven't put anything in your tea because we haven't had any in hours."

"This is mad," John said, letting out a bark of laughter. "This is one of those telly wind-up things." He looked at the ceiling, but saw nothing except cobwebs. "Very clever! You can let us out now."

"It's all real, John." Sherlock finally lowered his hands from his chin, letting them flop to his sides. His eyes were gluey with lack of sleep; John could see yellow dust gathered in the corners. "I've been going through it all night, and there's no other explanation. It's impossible to manufacture this level of detail; there will always be tells, always be something to let you know it's the modern day. This place smells old. The clothes are real. The forest was real. No trace of cleaning fluids, or electricity, or machine stitching."

"Maybe they're just very clever," John hissed, tapping on the wall with his knuckles.

"Not possible."

"But _Merlin_, Sherlock, and King bloody Arthur-"

"Prince. What do you know about the legend?"

John gave up on the wall and slid back down to the floor. He was hungry and thirsty, and the combination was making him feel nauseous. "Not much. King Arthur, the Holy Grail, something about a sword – they all come to a bad end, I'm not sure I want to be here." John stopped himself, and laughed again. "Listen to me – you've got me convinced it's real now."

"It is real, John; the sooner you accept it, the better." Sherlock clapped his hands. "What about Merlin, then – what do you know about him?"

"Mind palace drawing a blank, eh?"

"King Arthur has never come up on a case before; I've heard stories, yes, but I never thought I would need to remember them in any detail. What do you know about Merlin?"

John rolled his eyes. "Old bloke, long beard – sometimes carries a stick. If that boy was Merlin, he's missing a lot of the specs."

"Think, John!" Sherlock murmured, swivelling on the floor and hauling himself to his knees, gripping John's arms tightly. "Even I know this one, think – _what_ wasMerlin?"

John blinked, wincing as Sherlock's nails dug into his arms. "An old man?"

"Besides, that, John, people are young before they're old – what was Merlin?"

For a moment, John faltered, and then the penny dropped; he almost felt the electric signals in his brain click together. "A magician."

"Exactly." Sherlock let go. "I thought it was true, but I had to be sure…"

"That, yesterday – that thing that sent me flying, that was…magic?"

"Science has not ruled out the possibility of further science we do not yet understand."

"But, magic, Sherlock, really?"

Sherlock shrugged. "There will no doubt be an explanation, even if we do not know it."

"You're taking this very well," John muttered. "I would have thought you of all people would be desperate to understand it."

"At the moment, I'm more concerned with not dying here."

John looked around, but could only see stone. Stone and more cobwebs. "And 'here' really is Camelot?"

"Merlin says so, and we have no reason to doubt his word." Sherlock hauled himself to his feet and began to stretch; John heard joints crack. "I've been thinking; the only thing I can imagine that would somehow bring us here would be a colliding of two events, one in 221b and one here, in Camelot; two events in different places, hundreds of years apart, but with a combination of science and magic leading to consequences that can bend everything we know about time."

"Which is surprisingly little," John muttered. "We can try rationalise physics and quantum physics all we like, but I don't think most of us will ever be able to truly fathom something like time."

"Our event is clear to see – you knocked potassium into my film-developing."

"You keep leaving it in stupid places."

Sherlock stuck out his bottom lip. John got to his feet, wavered, stretched until the cricks in his neck were mostly loosened, and sighed. Sherlock's thoughts about the experiment made sense – the smoke, the blackout – but that didn't help his brain register what was happening. He wasn't sure it had hit him yet, or if it ever would; he felt like he was walking in fog.

"How are we going to get back, Sherlock?"

Sherlock shook his head. "We can't – not until we know what the event at this end was."  
"How can you be sure there was one?"

Sherlock smirked. "Magic."

* * *

Merlin had not slept well. He'd returned, exhausted, to his chambers to find Gaius waiting with a lecture and supper, and found it was impossible to have one without the other. Gaius had not been impressed by how long Merlin had been out. He was even less impressed by the paltry supplies Merlin had managed to drag back.

By the time he got to sleep, it was almost dawn, and Arthur wanted him up early for training. Merlin forced himself out of bed an hour early, pulled on his clothes in a daze and began scrounging in his room for supplies. Food he would have to come by with Arthur, but he did his best to find something for Sherlock and John to wear. He'd have to be careful not to get the clothes he was wearing dirty in the meantime, or he was going to be walking around naked.

He might have convinced himself that Sherlock and John had been a dream, if it weren't for Gaius's disapproving stare over the breakfast table.

"Where were you Merlin?" Arthur said, as soon as Merlin entered the room. Already, it was a mess. "Gaius told you to get herbs, not complete the twelve tasks of Hercules."

Merlin fixed a smile on his face. "I got lost."

Arthur laughed. "You got lost?"

"Yes."

"Only you could get lost in a forest you live next to." Arthur clapped him on the shoulder, a little too roughly. "Come on, you useless twerp. Help me with my armour."

* * *

Getting food proved to be the most difficult task Merlin had in front of him. Arthur trained hard, and Merlin managed to persuade him it was a better idea to eat in his chambers and rest, rather than having to make conversation with his father and Morgana, but past that, he ran into problems. Arthur never had been one to leave anything on his plate.

"What are you looking at, Merlin?"

Merlin blinked, realising he'd been eyeing up the chicken and vegetables as he wondered if there was a way to spirit them onto his person. Possibly into his boots. "What?"

"I said, what are you looking at?"

"Nothing," Merlin replied, too quickly.

Arthur scowled. "Go and tidy something."

Wearily, Merlin got to his feet. Arthur went back to his plate; already there was hardly anything but the odd carrot left. Sherlock and John had now been in the tunnels for almost a day, and he was sure neither of them had eaten in that time. They had the re-filled water skin, but between them it wouldn't last very long. His brain whirred as he clattered around stowing armour and putting clothes in drawers. Then, the platter of fruit that sat in the centre of Arthur's table caught his eye.

"What's that?" Merlin said, pointing.

"What's what?"

Arthur didn't look up from his plate. Merlin's eyes flashed. By the time Arthur raised his head, everything was in place.

"That." Merlin pointed at the plate a second time, then walked towards it and turned it around. "There's something _moving _in it." He reached his fingers into it and pulled a worm out of the grapes.

Arthur frowned. "Must have got in there by mistake. Just throw it out the window. It's only a worm."

"No, no," Merlin said, reaching for the platter and dragging it towards him. "We can't have a prince like you eating fruit that's gone off."  
"It's not off," Arthur said, narrowing his eyes. "What are you playing at?"

"Nothing!" Merlin scooped the platter into his arms. "I'll go get you a fresh one."

"Merlin! Come back here!"

"Sorry!" Merlin called as he made for the door, knocking over a metal bowl with a clang. "Can't hear you – be back in a minute!"

The door closed on Arthur's startled reply. The trip to the tunnels took far longer than Merlin would have liked – the platter was cumbersome and the stairs not in their finest condition – but he made it without mishap, glad that he'd had the good sense to carry the spare clothes around in his bag, because he would only have a few minutes before Arthur began looking for him.

Sherlock and John were propped against the wall where he'd left them, talking in low voices. John looked better, Sherlock looked pale, and both of them must have been half-starving because the look on their faces as he came into view with the plate of fruit was close to animalistic.

"Thank god for that," John muttered, reaching for the plate before Merlin could even set it down. "We thought you weren't coming." He put five of the grapes in his mouth and once and chewed.

Sherlock sighed and reached for an apple with restraint that Merlin felt was more for their benefit than his own. "Forgive John; we haven't eaten in at over a day."

"How long were you in the woods?" Merlin asked, settling himself cross-legged on the floor and pulling the spare clothes out of the bag.

Sherlock and John exchanged a glance. John shrugged, then swallowed. "At least six hours; it was the middle of the afternoon when we arrived, if the sun was anything to go by."

"Have you got any more water?" Sherlock asked.

Merlin shook his head. "I haven't had the chance – Arthur doesn't give me much time off."

John cocked an eyebrow. "So you know him personally then?"

"I'm his manservant."

Sherlock looked like he was going to smirk, but then he took another apple.

"I see," John murmured, reaching for more grapes. "So…you really are Merlin?"

"Why would I lie to you?" Merlin pulled out the clothes and thrust them in Sherlock and John's direction. "Put these on." Now that he was back with them, Merlin was itching to know exactly where they had come from; he imagined it had to be a long way for them to be dressed in such a manner, and know so little about Camelot's state of affairs. They'd known of Arthur, of course, which was something. "I don't have much time, but I promise I'll come back at night, with water."

Sherlock had one of Merlin's shirts pinched between finger and thumb and was eyeing it apprehensively. John kicked him.

"Thank you," John said, smiling. "Thank you for helping us."

Merlin nodded and got quickly to his feet. "I've got to go. Arthur will be looking for me; I ran off with his fruit plate."

Sherlock snorted. John smiled. "Well, if you could tell him, I'd ask you to let him know we appreciate it."

Merlin hurried from the room. Before he'd even made it to the kitchens, he could hear Arthur calling his name.

* * *

**Thanks for reading, feedback welcome! **

**I'm hoping to have the next chapter up early, perhaps Sunday.**

**To be continued. **


	4. Chapter 4

"We need to think of something to tell him," John said, trying to force his head through the top of Merlin's tunic; the collar was far too tight. "About where we came from."

Sherlock had managed the other tunic well enough, although the sleeves were an inch or two short, and was battling with the trousers, which fit around the waist but were far too small length-wise. John's trousers, on the other hand, were pinching horribly at his hips and crotch, and he'd had to roll the bottoms up, much to Sherlock's amusement. The pair of them looked like a couple of ill-dressed shop dummies.

"We should tell him the truth." Sherlock finally managed to wrench the trousers down a little, so John could only see his ankles and socks. Merlin hadn't provided them with shoes; John presumed they would have to wear their own, and hope no-one noticed. Not that they were expecting to be found.

"We can't tell him the truth," John muttered. "He wouldn't like it."

"Why shouldn't we? We accepted that we were in the past."

"That's different."

Sherlock gave up on trying to get his trousers to hang lower and slid to the floor. He had to sit with his legs straight to prevent his knees coming through the material. "Why is it different?"

"It just is."

"Because we have modern mind-sets, and he doesn't?"

John flushed. "That wasn't what I-"

"Even if that were true," Sherlock cut in, "it's not as if he's unfamiliar with the new and strange. He can do magic."

John shook his head, joined Sherlock on the floor, and wished there were some grapes left. "I never thought I'd hear you use that word."

"Only in place of a scientific term for it," Sherlock said, turning up his nose a little.

"So, say we tell him the truth. Even if he believes us, how is he going to help? Do you think the event – the one that coincided with ours – had something to do with him?"

"Undoubtedly," Sherlock replied, steepling his hands under his chin in his 'I am doing my very clever thinking' pose. "If we have to get back, we need him to recreate it."

"You think that'll send us back? Doing everything a second time?"

Sherlock inclined his head. "It's the only thing I can think of. It might not get us back to exactly the same place, but it's worth a try."

"Are you telling me we could end up in Australia?"

"Quite possibly."

John rolled his eyes. "Wonderful. Just wonderful. And how the hell are we supposed to 'recreate' your experiment – they haven't even invented the camera yet, let alone film-developing solution."  
Sherlock's mouth twisted a little. "Mm. That is the most troubling aspect of the enterprise. However, it's possible we do not have to replicate the actual experiment – the basic elements I was using should be easy to come by. We might not need the entire thing; just enough of it."

"In which case, we might not get back the whole way – just some of it," John replied dryly, drawing a finger idly along the rim of the silver plate. He watched his distorted reflection make strange faces at him and wondered if Alice in Wonderland ever felt the same way he did now; staring into a mirror with a mixture of nausea and excitement. "What are they, then, these elements?"

"Water, silver, salts, fixer and shortstop – that's a strong acid and a weak one – ammonia. I was using colour film, so dye as well."

"And potassium," John muttered. "That was the cause of the whole thing – where the hell are we supposed to find potassium in Camelot, of all places?"

"I'm sure we can think of something," Sherlock said. His voice was cold, but John couldn't tell if it was the chill of the stone eating into him, as it was eating into John, or the simple fact that, no matter what he said, he didn't believe that they could do it.

"Sherlock?"

"Mm?"

John opened his mouth, then shut it again. There was no point in speaking; there was no point in trying to understand what was happening. "Nothing. You should get some sleep."

"I don't need-"

"Yes you do. I'll wake you if something happens."

Sherlock grunted, but John saw his eyes slip closed. The passage was very quiet without him. Quiet and sinister. There was a torch in the corner that he didn't remember Merlin bringing – he must have done it when John was still battling with his concussion – but it was beginning to burn low, and John didn't have anything on him that would relight it. Soon, he would be alone in the total darkness.

Desperate to do something before the light went, John started to go through his pockets. He knew that he'd left his phone on an armchair at the flat, and that it wouldn't work here anyway, but he was still disappointed to find that it hadn't magically reappeared. His watch had stopped; he realised with a jolt that for the first time in a long while, he wasn't sure what time it was. He would have to ask Sherlock what year clocks were invented.

His other pockets only turned out a chewing gum wrapper, a few scraps of paper, and a stubby pencil he'd picked up free from somewhere. He sighed. Sherlock grumbled in his sleep. The light flickered.

John picked up the pencil only to give his hands something to do, and found the least grubby piece of paper. On it he wrote, in the order Sherlock had spoken them, the chemicals they would need.

He was a doctor. He had to know how to get some of them.

Water was self-evident, as was salt. He was fairly sure that the plate Merlin had brought the fruit on was silver, and the clothes they'd been brought did have colours on them, which meant dye was available. Having Merlin get it might be more of a problem.

Acid – a strong and a weak one. John paused, his tongue between his lips.

"I was thinking of wine," Sherlock said quietly, his voice hoarse and tired.

John jumped. "You're supposed to be sleeping."

"And you're probably supposed to be at work by now, but here we are."

The pencil clattered to the floor. John didn't bother to pick it up. "Do you think time's still moving back home?"

"We'll only know when we get back."

John turned and looked Sherlock full in the face. "You really believe we can?"

Sherlock didn't meet his eyes. "Wine has a pH of four, if we're lucky. Cider's weaker. Those are our acids."

John retrieved the pencil and scribbled them down, squinting as the light began to sputter. "What about ammonia?"

Sherlock smirked. "Bird droppings."

John pulled a face. "Merlin is going to love us." He crossed off ammonia, but potassium still hovered irritatingly in the corner. "Where the hell are we going to get our hands on potassium? When were bananas brought to England?"

"Not for centuries," Sherlock muttered. "Besides, I'm not sure a banana would cut it."

John tipped his head back against the wall and groaned, closing his eyes and racking his brain to remember his university chemistry. Surprisingly enough, none of it had been about how to get potassium in the Middle Ages.

"Potash!" Sherlock exclaimed.

For a moment, John almost said 'bless you'. "Sorry?"

"Potassium is made from potash."

"Is it used in anything?"

"It's found in the ground." Sherlock clicked his tongue. "There'll be a mine, somewhere in Britain, I'm sure of it."

"Where in Britain?" John said, still sceptical; nothing Sherlock was saying was making his heart leap with joy.

"No idea." Sherlock waved a hand as John opened his mouth again. "Shut up. Mind palace."  
John rolled his eyes. "You know that even if we somehow cobble together your experiment, we still need to find out what the corresponding event was?"

Sherlock was already lost inside his own head. John sighed, fixed his eyes on the torch, and kept them there until it burned down completely. The room went dark. Sherlock didn't even notice.

* * *

Midnight found Merlin sneaking down passages with a loaf of bread and a second water skin, wishing that he could have brought more, but knowing he couldn't risk it.

The passage was pitch black. For a moment, Merlin panicked, thinking that Sherlock and John had somehow been found out, until he heard John speak. "Hello?"

"Just me," Merlin said, appreciating that John hadn't outright used his name; if it had been someone else, he wouldn't have given him away. "One moment."

He hadn't brought any flint with him, but seeing as Sherlock and John already knew, he lit the torch with magic. It sputtered to life, caught a draft, and narrowly missed setting his hair alight.

Sherlock and John were still against the wall. John was looking at Merlin intently, but Sherlock was staring straight ahead, unmoving. His eyes were glassy. It was unnerving; almost like he was dead.

"Is he alright?"

John turned and looked at Sherlock; Merlin could have sworn he saw a smirk curve his lips, just for a moment. "Sherlock? He's fine, but don't expect him to say anything. He's in his mind palace."

"His what?"

"It's where he stores his information; like a personal library."

Merlin raised an eyebrow. The man must have an incredible memory. "He must be very clever."

John snorted. "Most of the time. The rest of the time he's usually cooking up some completely stupid scheme to get us both killed."

"Sherlock said you were a physician," Merlin said, settling himself on the floor and placing the bread on the stolen plate. "I wouldn't have thought that was a dangerous profession."

John reached for the bread, broke it roughly in half, and took the smaller piece for himself. "You'd be surprised. Sherlock is a…well, sort of a detective."

The word meant nothing to Merlin, and he said so.

"A policeman…no, you don't have them yet – a…basically, people hire him to find things out. Like, if someone thinks someone has been murdered, and they want to prove it in a court. Or they want to find a missing person. Or if someone is having an affair."

"I see – like a witch finder, but not for sorcery."

"Witch finder?" John pulled a face. There was bread stuck between his teeth, but Merlin didn't point it out. "As in, hunt-down-witches-and-burn-them-at-the-stake?"

"Not just witches," Merlin muttered. "Wizards and sorcerers of any kind, or any gender. Thankfully, they don't often come here." He sighed and tipped his head back, rotating his head until his shoulders began to loosen – Arthur had made him scrub his boots for running off, and his muscles were already starting to protest. "You have witch finders, then, where you're from?"

"No. Not in London."

"It must be a long way from here," Merlin said, frowning as he tried to imagine where exactly it might be. "How did you end up in the forest?"

John shot a glance at Sherlock, still glassy-eyed, still unmoving, and sighed. "It's a long story. I hope you weren't planning on getting any sleep."

Merlin had been, but he shook his head all the same.

* * *

**My chemistry skills are very poor; I've been using the internet to help me out, but a lot of it was pretty complex, so I really apologise for any technical mistakes I'm going to make from now on.**

**Thanks for reading, feedback welcome!**

**To be continued. **


	5. Chapter 5

The tale was long and John's throat sore, and by the time he'd finished explaining, and passed his scribbled list to Merlin, he was beginning to wish that the whole of Camelot, Merlin included, was only a part of a concussion-induced hallucination.

But it wasn't, because Merlin's sleeve brushed his hand as he took the paper, and it was definitely solid.

The 'we're from the future' part had been the hardest to get across, although, as Sherlock had predicted, not as hard as John had expected. As someone who could conjure fire, Merlin probably didn't find the concept entirely improbable. He did, however, ask an awful lot of awkward questions that John answered either with neutral grunts or 'I don't know'. Although Merlin was aware that Arthur was remembered, even hundreds of years later – was it just John, or did he light up a little at that? – John didn't think it was prudent to tell him exactly how the whole thing worked out. Not that he knew with any accuracy, of course.

It made him sad, to think that, where he came from, Merlin was already dead.

"What's this?" Merlin asked, pointing to the squiggle that read 'potassium/potash'. "I've never heard of it."

"Probably wasn't discovered until the 1800s," John muttered. "That's what Sherlock's looking for."

"In his mind library?"

John laughed, wishing that Sherlock could have heard his palace reduced to a library. "Yes. But the other things, do you think you can get them for us?"  
Merlin frowned, tapping at his chin. "As far as I know, although I have no idea what amounts you'd need."

"To be honest, neither do we."

"Then how do you know it's going to work?"

"We don't," John murmured. "Not a bloody clue. All we can do is try."

Merlin sighed, glancing around the bare room. "I'll do my best."

John smiled. "Thank you." He checked his watch out of instinct, and then remembered it was broken. "You look tired."

Merlin added to the statement by yawning until John heard his jaw crack. "Arthur had me up early for training." He got slowly to his feet, handing the last of the bread to John.

"You'll have to tell me more about Arthur, when you come back," John said. "He sounds like an interesting person."

"A prat. But yes, I suppose he is." Merlin had smiled at the mention of Arthur's name; his eyes shone in the torchlight. "Goodnight."

"Good-wait!" John's eyes, already half-closed, snapped open. "Sherlock will kill me if I don't ask you – what were you doing say, six hours before you ran into us?"

Merlin frowned, swaying sleepily. "What?"

"Sherlock thinks that's the reason you were the first person to find us – that we ended up here because of the things on those list, and the fact that you were doing something beforehand." He leaned forward. "Something to do with magic."

"I'm not sure."

"Think about it," John said. "Please."

Merlin nodded, turned, and left. John put the remains of the bread on the plate, and then tried to sleep.

* * *

Merlin slept badly, desperate as he was for the rest. There was too much going through his mind, too much he knew he had to do.

John was from the future. And Sherlock. Fascinating.

But they didn't belong here, that much was certain. If they were to get home, Merlin had to work on getting the supplies as soon as possible. It was just like brewing a medicine, or potion, he told himself as he sat up, despite not having slept for more than a couple of hours. It was still dark outside. He reckoned he had while before Gaius woke or Arthur started demanding his presence.

The least pleasant task he did first knowing that, whatever he had to do later, it couldn't be half as bad as sneaking into the henhouse and scraping sticky white droppings off the floor with his neckerchief pulled up over his nose and mouth. He placed the bottle full of its foul-smelling contents in his bag, alongside another water skin and a few pinches of salt from Gaius's cupboard. Gaius had a lot of silver trinkets, but would notice immediately if any of them went missing. Arthur, on the other hand, was usually more clueless. He also often had wine for dinner, and he rarely drank all of it.

For cider, Merlin would have to go to the tavern – his mouth curved into a smile at the thought of what Arthur would say about that. The rest would have to wait until the right opportunity came along.

"You're up early," was the first thing Gaius said when he found Merlin setting out breakfast. Gaius's eyes strayed towards Merlin's bedroom; the mess on the floor was painfully obvious. "I see you haven't done anything useful with your time."

Merlin didn't reply, too busy racking his brains to remember what he had been doing six hours before he came upon Sherlock and John. It had been before he went into the woods, before Gaius told him to go. He had been with Arthur then, he was sure. What they had been doing? Training had probably been finished; yes, he thought, it definitely had. Arthur had cut his arm when he dodged a well-timed blow and stumbled into the sword rack – much to Merlin's amusement. Not that Arthur would have allowed him to laugh.

"Merlin?"

Merlin jerked his head up. "Mm?"

"Have you been listening to a word I've been saying?"

"You asked me why I haven't being doing anything useful with my time."

Gaius rolled his eyes. "That was before, Merlin! Try and keep up."

"What's potash?"

Gaius had his mouth half-open, and he glowered when Merlin interrupted him. "I have no idea."

Merlin felt himself deflate a little. If Gaius didn't know, he wasn't sure anyone would. He got hastily to his feet and made his way towards the door. "I have to go."

"Merlin! I haven't finished with you."

"Arthur's calling me," Merlin shot back, closing the door before Gaius could listen to verify the fact.

It wouldn't be long before his lie turned into the reality. Merlin could hear the salt shifting in his bag as he half-walked, half-jogged to the library. He found no reference to potash or potassium, but that hardly surprised him.

As he made his way to the kitchens to collect Arthur's breakfast, he had a sudden flash of remembrance as to what had happened when he bandaged Arthur's arm; a squire had brought a pitcher of wine and another of water. Merlin remembered glancing at Arthur's shadow and thinking that it must be exactly midday, because it was so small he could barely see it, and his fingers had slipped as he bandaged Arthur's arm, accidently sticking him with the pin he was using. Arthur had winced, and Merlin had braced himself for a verbal buffeting.

But, for some reason, Arthur had laughed. Something had swelled in Merlin's stomach at that – relief, perhaps, and something else, that had made him want to laugh too. And as the feeling welled up inside him, he'd felt his fingertips spark. It had been an instant, so brief that Arthur hadn't noticed – Merlin had barely realised it himself until the moment had passed.

Magic.

It hit Merlin then that, if they were going to recreate an event that had happened six hours before he had found Sherlock and John, they were going to need Arthur to do it.

* * *

"Boulby mine."

John hadn't realised he'd been sleeping until Sherlock spoke, and he jerked his head up, almost knocking the plate over. "Hmf?" he murmured, clutching at the loaf with one hand and rubbing his eyes with the other. "What?"

Sherlock looked like he was halfway to hell; the bags on his face could have been used for hanging pictures, and he was horribly pale. John pressed the bread onto him anyway, forcing him to eat before he carried on.

"What was that you were saying?" John said, as the last of the bread vanished.

Sherlock swallowed, reached for the water skin and sipped. "I said, Boulby mine. One of Britain's potash sources; if we're going to get enough potassium for this, we're going to need to mine it."  
John raised an eyebrow. "And how, exactly, do you expect to do that? This is the middle ages. I doubt even you can built a power drill out of cobwebs and lumps of stone, which is pretty much all that seems to be available down here."

"Don't be obtuse, John. We have magic."

The word still sounded strange on Sherlock's lips; John had to force himself to hold his tongue and stop repeating the fact. "Even if we manage to get this potash, how do you expect to make potassium out of it without chemicals or electricity?"

Sherlock shook his head. "Hopefully, we won't have to; nothing we're recreating will be totally pure in the first place – we simply don't have the technology. If this is going to work, then the potash should do. If it's not going to work, then having pure potassium won't help us."

"Great." John resisted the urge to bang his head against the wall as his stomach contracted; he was beginning to realise just how hopeless the whole thing was beginning to sound. Really, if it hadn't been for the magic, he would have been in despair a long time ago. "And how far away is this mine?"

"That depends on where we are now."

Most historians speculate Camelot was in the south left of Wales," John said, surprising himself as he dredged up the information from a quiz show he'd seen not long ago.

"In which case…" Sherlock closed his eyes for a moment. "Boulby is not far from Scarborough; I would argue, around three hundred miles. It'd take well over a week to get there by foot. Less, if we could find a horse."

"How are we going to find the way, Sherlock?"

Sherlock opened his mouth, and then faltered. His voice came out very quiet. "I don't know."

This time, John really did smack his head against the wall; he leaned back a little too enthusiastically and let out a sigh that dragged at his lungs until they were hollow. He felt hollow. "We're never going to make it."

* * *

Merlin, when they explained it to him, thought that they were joking. When it became apparent that they weren't, Merlin found he didn't have the strength to tell them what the chances of making it were; it wasn't as if they had much to lose. The longer they stayed in Camelot, the more chance they had of being caught. He half-formulated some sort of speech in his mind about the advantages of starting a new life here and forgetting about home, but one look at them was enough to tell him that it wouldn't work. He wouldn't have wanted it to work. He doubted they'd last a week.

In the end, all he did was nod. The next day, he pocketed one of Arthur's silver forks. Two days after that, he managed to spirit away the dirty water he'd used to wash Arthur's new red tunic in, in the hope that it would be soaked with enough dye for their purposes. Sherlock looked unconvinced, but John thanked him anyway.

"How are you going to get us out?" John asked him, as he was packing away the skin full of still-pink water. "Aren't there guards or…or knights?" He pronounced the word as if he didn't believe it.

Merlin inclined his head. "If we leave in the day, they won't try and stop us."

Sherlock spoke before John could open his mouth. "We have the clothes; so long as we don't start talking about thermonuclear energy, I'm sure they'll let us pass."

Merlin didn't ask what thermonuclear energy was, much as he wanted to. "Do you know the way?" he said instead.

Sherlock and John exchanged uneasy glances. John sighed. "Sherlock's been trying, but…"

"But I have visited the place only once in my life, when I was five, and I deleted most of the experience immediately afterwards." Sherlock's voice was very clipped; if Merlin hadn't known better, he would have thought he was experiencing regret.

John sighed, and scrubbed a hand across his face. "You don't know the way, do you?"

"If I do know the place, it must have a different name."

"What about magic?"

John flinched as the word came out of Sherlock's mouth, but Merlin nodded. "Perhaps – if you could picture the place, I could cast a locater spell that would light the way."

"Wouldn't people notice us following a light?" John asked. He sounded scared; Merlin, in a desperate attempt to press onto them the secrecy of his sorcery, might have been a little too graphic in his descriptions of what would happen if he was caught.

"I will be the only one who can see it."

They nodded. That Merlin was coming with them all the way had been presumed from the outset.

"What about your event?" John said. "Did you remember?"

Merlin cheeks flushed, and he felt a spasm of guilt, although he wasn't sure why. Perhaps because it had been so stupid; if Arthur had happened look down, he would have had to try hard to miss what had happened right under his nose. "Yes."

Sherlock twitched, and was suddenly paying more attention. "Was it magic?"

"Yes."

Sherlock smirked at John, who rolled his eyes. "I never said that you were wrong, Sherlock."

Merlin sighed. "I have to go."

Sherlock turned away, looking disinterested again. John smiled. "Thank you."

Merlin left, already groping for an excuse he could give to Gaius about doing something for Arthur that would last the amount of time it took to escort two people across the country. He doubted it would take him long to work out he was missing, but by the time he sent anyone after him, it would be too late. Once he got Sherlock and John back home, or tried, he could make up any explanation.

Of course, there was still Arthur to bring with them. Merlin didn't yet have a good excuse to give him.

* * *

The guards came when they were sleeping. It was bad luck that they happened to walk by, bad luck that John was so exhausted that he didn't hear, and Sherlock…well, Sherlock, once he started sleeping, couldn't be awoken by more than a thunderstorm.

It was the rap of something metal against stone that brought John, with a jerk to, out of his dreams, which had been disturbing at best and downright terrifying at worst; he didn't think he'd slept properly since their arrival, and he didn't doubt that he wouldn't sleep a full night until they were home. If they got home. He kept trying not to think in 'ifs', but it was hard.

The rap came again. John blinked, resisting the urge to sniff, because the sound was very, very close, and John didn't think that the stone walls would do anything to muffle the sound. Slowly, being inordinately careful not to shift and knock the plate, he reached over and tapped Sherlock on the shoulder. Sherlock shifted, but didn't wake. John shook him a little and then, when Sherlock continued to doze, clapped a hand over Sherlock's mouth and kicked him hard in the shin. Sherlock shot awake like a startled deer, arms flailing.

"Shh!" John breathed, not daring to raise his voice above a hiss. Sherlock's eyes flicked to him, glowing in the half-light that, John realised, was not their own torch, which had burned out hours ago, but one that must have been lit further down the passage. John's palm was wet as he removed it from Sherlock's mouth, breath condensing in the chill of the stone walls.

There were voices coming from the direction of the light. As Sherlock began to shift into the shadowy corner of the room, dragging John with him, John strained his ears, listening. The men were loud, and doing nothing to hide their presence – one or two might even have been drunk.

"I can't believe we have to come all the way down here…"

"It's either that or use the blocked one and, trust me, you don't want to."

There was a smattering of laughs, and the sound of boots on stone as the light drew nearer. John leaned close to Sherlock and whispered, so quietly he was doing little more than breathing. "They must have come to use the toilet."

Sherlock nodded. His eyes were very bright. The guards milled around for a second – John saw one, and then another, cross the entrance to the small room they were huddled in, but no-one gave them a second look; there were too many shadows. One of the guards came forward, standing in the doorway, facing down the passage and calling to the others, holding a torch aloft.

As he did so, the light caught the silver plate, which flashed in the dim light, making John blink. He felt Sherlock twitch beside him. For a moment, he allowed himself to believe no-one had noticed. And then a second guard tapped the shoulder of the man with the torch, and pointed. John knew that he and Sherlock were too far back to be seen, but the plate was in plain view. The guard took a step into the room.

John bunched his fists, getting ready to fight, but Sherlock put a hand on his bad shoulder and squeezed tightly, forcing him to expend all his energy trying not to cry out. The light hit the room and spread, and even though his eyes were watering from the sudden brightness John saw the guard's face shift into a startled, wide-eyed expression as he caught sight of them.

Sherlock suddenly released John's shoulder and pushed him forward, straight into the path of the man, who let out a yell and raised his sword, even as John bunched his hands into fists, trying to work out how to hit someone dressed all in metal. He didn't get the chance; the guard's friends had streamed into the room before he could get his balance. He was vaguely aware of shuffling behind him, and then Sherlock was by his side, being dragged to his feet. A hand rested on John's arm and held it so tightly he thought his bones would break.

"Did you steal this?"

One of the guards brandished the silver plate in John's face, almost taking his nose off in the process. John tried to force a 'no' past his lips, but his mouth was dry with panic, and the guards didn't seem to be listening anyway; the chorus of their voices was almost deafening as they began to drag him up the corridor, away from the safety of their little room, Sherlock stumbling along beside him.

* * *

**This turned into a bit of a bumper chapter, thanks to some advice from The Crossover Addict, and I get the feeling the next one will be longer too. I was worried about it being difficult to follow, so please let me know if I'm getting horribly tangled. **

**Thanks for reading, feedback welcome!**

**To be continued. **


	6. Chapter 6

"What did you do that for?" John muttered, once they had been forced into a cell that contained nothing but straw, a bucket, and a bad smell. "Holding me back and then pushing me out? He could have killed me."

Sherlock poked the damp straw with his foot and pulled a face, then leaned against the wall. It was wet, and left green slime on his tunic. "I knew what I was doing."

"Care to let me in on it, then?"

"When I pushed you out, you were off balance, and the guard could see that; it would have been dishonourable to kill you. Attacking the guard yourself wouldn't have done you any good. Besides, I needed a distraction, so I could hide our things before he got a good look at what I was doing."

John frowned, and then realised that the guards hadn't brought the bags containing their precious supplies. "Where did you put them?"

"A small hole in the wall. They should be safe there."

John ran his hand along one of the bars; it was rusty and sticky, but disappointingly sturdy. "Safe for what? Rotting after we've been executed for stealing a bloody plate?"

"I don't think-"

"People have been executed for less." John gave up on the bars and began to pace, four across, four back, four across, four back, until he felt dizzy. He didn't like it here; he didn't like being confined. The stone passage had been bad enough, but this was…hellish. There was some natural light, but it brought him no comfort; all it told him was that it would be soon be morning, and the guards would be back to take them…god knew where. Hopefully not a scaffold.

"Breathe, John."

"I am breathing!" John snapped, coming to a halt and almost slipping on the wet floor. He resisted the urge to snarl, and only partially succeeded. "This is ridiculous!"  
Sherlock had his arms by his side. His shoulders were loose. "All we need to do is think of a story to tell them."

John laughed then, but it was so forced it made his lungs pulse. "It'd better be a damn good story, Sherlock Holmes."

Sherlock sighed. "We can try."

John couldn't bring himself to do anything but nod. For a while he racked his brain, trying to come up with a reason as to why they were hiding in the bowels of the castle in possession of a silver plate with a coat of arms on it, but before he could get anything better than the excuse of 'we found and were returning it' the footsteps sounded again. John jumped, and Sherlock's arms jerked, shoulders tensing. John turned so quickly to the window that his neck clicked. The light looked no different than before; it was far from morning.

"What the hell…" he growled. "I thought we had more time!"

Another thud. John swallowed; something was definitely wrong. The guards shouldn't have been coming back for hours yet, and inside the cell they were completely defenceless. John looked around frantically, but all his eyes lighted on was the metal bucket. He pulled a face, but there wasn't time to be disgusted. Hastily, he reached for it. It was empty and poorly made, but he reckoned he could pack a good blow with it if he had to.

He would have to.

The torches had gone out down the corridor; the only light came from the window, and it was weak. Shadows flickered in the corners of John's eyes as someone approached the gate, and unlocked it. Sherlock tensed beside him, gripping his sleeve. John held his breath. The dawn sun reflected off metal; a man in armour, carrying a sword. The door creaked open.

John leapt forward and swung the bucket straight at the man's head.

* * *

By the time Merlin found out about the arrests, it was too late to stop proceedings going ahead. A small panel was already being arranged for the morning, and the penalty could be anything from a fine to death, depending on the mood of the people attending. Theft – of a plate, a plate he had brought to them, of all the stupid, _stupid_ things, he thought, pacing his room until he felt his shoes would wear holes in the floor.

Sherlock and John wouldn't understand the court proceedings; they might be taken for madmen, or sorcerers. They could give him away in a pinch, if they said the wrong thing.

He couldn't allow it to come to trial. It was too dangerous.

Merlin looked out of the window. It was still dark, but only just. Arthur would be at the trial – too much of a petty case for the king himself – and Arthur was a fair man, but it was not guarantee. He might be overruled. He might be suspicious of Sherlock and John, the way the spoke, the way they acted – especially Sherlock.

Merlin slowed his pacing, coming to an abrupt halt by the door. There was only one thing for it; he had to get to Arthur first.

* * *

"Merlin?" Arthur grunted, rolling over and almost falling out of the bed. Merlin ruthlessly threw back the curtains, allowing what light there was to stream into the room.

"Up and at 'em!" he called, forcing cheeriness into his voice; the more nervous he sounded, the more suspicious Arthur would be.

Arthur let out a long groan. "Is'not time to go yet?"

Merlin resisted the urge to smirk; listening to Arthur in the mornings was like learning another language. "You would have had to get up in an hour anyway."

"What?" Arthur rolled over the other way. "Go get me up in an hour then."

"I have to talk to you."

A pillow sailed through the air and struck him on the shoulder. "This is not the time, Merlin."

Merlin hesitated. On the one hand, he'd known getting Arthur up early had been a risk. On the other, time was running out.

"Please."

There was a moment of hesitation, and then Arthur sat up in bed, pulling the covers with him. His eyes were crusty with sleep, but he scrubbed a hand over them. "What?" He was trying to look irritated, but it wasn't working; Merlin could tell he was worried. "What is it?"

"You know about the trial today?"

Arthur rolled his eyes. "Of course I do – that's why I'm up at this ungodly hour." Arthur hesitated a moment. "What has this got to do with you?"

"The two men-"

"For god's sake Merlin, you're not going to tell me you know them?"

Merlin bit his lip. Arthur groaned and swung his legs over the side of the bed.

"I can't do anything about it, you know that, Merlin. They were caught stealing, they have to face the consequences."

"They didn't steal!"

Arthur had hauled himself out of bed and gone behind the screen to dress; his voice was slightly muffled as he talked. "They were caught hiding in the tunnels with a royal plate."

"I gave it to them."

Arthur popped his head above the screen, eyebrow raised. "You stole it?" He looked almost amused at the thought – his mouth was crooked and slightly open – but there was more to his voice than humour. Suspicion. Great.

Merlin debated about lying for a moment, and then decided that some version of the truth would serve him best. "They were just passing through, they needed a place to stay; I took them some food. I was going to bring the plate back."

Arthur sniffed, and disappeared behind the screen again. "What do you mean, 'passing through'? Where are they from?"

"A way off. London."

"Never heard of it. How do you know them?"

"They stayed in Ealdor once, when I was young. They…travel."

Arthur emerged from behind the screen in his vest and Merlin dutifully went to fetch the rest of his clothes, beginning to lace the tunic without really paying attention; he kept getting the strings tangled.

"Why couldn't they stay with you?" Arthur asked. "Why were they skulking in the tunnels?"

"There wasn't space in my rooms. And there's a…leak. They were only going to be here one night; they said they didn't mind exploring the tunnels a bit. I took them some food, on one of the plates. It would have been back by morning."

Arthur sighed, and lifted his arms so Merlin could lace the sides of the shirt. "Then you'll have to testify to that at the trial."

"I can't." It came out before he had time to stop it, and he froze in his lacing, fingers slipping completely. "I mean…"

Arthur lowered his arms and stepped back a pace. "Who are these people, Merlin? Even if I believe they aren't thieves, I don't think you're telling me the truth."

Merlin's mind raced, but everything had gone blank; he didn't fully understand what was going on himself, and that made it hard to come up with something Arthur would believe. He couldn't do it; not in the few seconds he had before Arthur got angry, or disappointed, and simply walked away.

"Are they druids?"

Merlin hovered on the edge, wondering what to say, and who would get killed if he did say it. "No."

"Sorcerers?"

"No."

Arthur's shoulders relaxed a little. Merlin took his chance.

"Trust me. Please."

With a sigh, Arthur sat on the bed. Merlin automatically went to sit beside him, and began to lace the other side of his shirt. "Why are you telling me this? Why not just…let the trial go ahead? It's _theft_, Merlin, they might get a fine, or a warning."

"Or they might be branded. Or worse." Merlin turned to Arthur, resisting the urge to put a hand on his arm and force him to look him in the eye; Arthur would look him in the eye when Arthur felt like it. That was the way things worked. "Can you guarantee that they'll be alright? Can you _promise_ me?"

Arthur looked him in the face at last, but didn't seem able to hold his gaze. His eyes flicked away again, hovered somewhere in the distance, and then he got up, so quickly that Merlin lost his hold on the bed and slid to the floor with a bump.

"Dammit Merlin!" Arthur struck out at the nearest table, sending a candelabra to the floor with a clatter. "Why weren't you more bloody sensible?"

Merlin stayed where he was, legs curled underneath him, waiting. Arthur paced the room, once, twice, and then came to a halt, folding his arms. "Get off the floor, then."

Merlin looked up. Arthur glowered at him.

"We've got less than two hours before dawn. You have a plan?"

"Sort of."

"Well, no 'sort of' plan is going to work when you're sitting on the floor. Let's have it. I'm assuming you need me?"

And he did, Merlin thought as he scrambled to his feet, in more ways than one. Because not only could Arthur help them get there, he _needed _to come. If the two events were to be replicated, Arthur had to be there. And Merlin would have to perform all sorts of magic in front of him, and hope he didn't notice.

He'd cross that bridge later.

* * *

The bucket flew out of John's hands before it could connect with the person's head, whizzing back into a wall and – astonishingly – not making a sound. John froze.

"It's me!" Merlin hissed, raising his helmet. It was ridiculously oversized; John wondered for a moment where on earth he'd got it. "I'm here to get you out."

"Thank god," John muttered, letting his arms go limp.

Sherlock was already on his feet. "Where are our things?"

"Here." Merlin tugged the satchels out from under his chainmail and handed them over. "We have to go, we've got less than an hour."

"Where are we going?"

"Out of Camelot," Merlin said, leaning into the passage and scanning it. He nodded, jammed his helmet back on his head, and stepped out of the cell. "Come on, the watch will be awake any second. If anyone stops us pretend that I'm a guard."

Sherlock snorted a little at that, and John had to admit that Merlin looked very far from a knight, in his oversized helmet and too-short chainmail. Still, perhaps it would be enough. It had fooled him for a moment.

Merlin led them through a warren of passages and doors and stone walls and torches, until John's eyes were burning from the fragmented light and his feet aching from the hard floors; too many days locked away in the bowels of the castle, too many days without proper sleep. Sherlock was breathing heavily. Merlin wasn't even sweating, and that was with the helmet. John had never thought of himself as unfit, but he would have given a lot of money to have been able to jump into a cab.

They came out of a grate in the side of the castle that Merlin had to loosen with magic – for once, John didn't allow himself to marvel – and made hastily for the woods, Merlin two steps ahead and shedding his armour as he went. The bags of supplies Sherlock was holding bounced against John's hip every other step. The sun was rising, and for the first time in days, John allowed himself to breathe deeply. Fresh air hit him like a drug, and the ache in his feet and legs dulled a little. Sherlock turned to look at him, and smiled.

They were laughing by the time they reached the forest, and Merlin had to hush them before they'd gone more than a hundred metres into the trees. "Now isn't the time," he growled. "There could be guards looking for us."

John pinched his mouth shut. Sherlock swallowed. "Sorry."

Merlin rolled his eyes, then brought them to a halt in front of a tree with roots that stretched like a spider web around their feet. "I'll cast the spell that'll show us the way now. Sherlock, do you remember what the place looked like?"

Sherlock thought for a moment, forehead crinkling, and then nodded. "I think so. I was very young, and it would have looked…different."

"Could you picture it as if it was on a map?"

Sherlock considered again, then nodded.

"Good. Try and combine those two images; I'll know if it's worked."

Sherlock closed his eyes. John could see he'd been rubbing his eyes – several of his eyelashes were askew, half detached and hanging, until they actually got into his eye and he'd start complaining to John. Despite everything, John found himself beginning to smile again.

Merlin put a hand to Sherlock's forehead and held it there a moment, muttering to himself. His eyes flashed; John almost missed it in the dawn light, but it definitely happened.

More things in heaven and earth, he reminded himself, not knowing where the quote was from, but deciding it made him feel clever.

"Alright," Merlin said, looking around them. "You can open your eyes."

"Did it work?" Sherlock murmured, scrubbing a hand over his face; John saw more eyelashes go for a burton, and had to fight to keep the smirk off his face.

Merlin turned a full circle, and then nodded. "This way. North."

John squinted, but couldn't see anything. Just like Merlin had said. He would have preferred not to get him involved, but he'd known all along there wasn't a choice.

Sherlock gave him a look, as if to say 'you know we really have to'. John nodded. "Alright. Lead the way."

* * *

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**To be continued. **


	7. Chapter 7

Merlin heard the horse's hooves and ducked into the shrubbery just in case, dragging John and Sherlock with him, but he needn't have worried; it was only Arthur, riding his own horse and leading Merlin's alongside. Both animals had packs and water skins. Arthur had even remembered to bring spare weapons. Merlin was impressed, but he resisted the urge to make a sarcastic comment.

"Arthur!"

Arthur reigned the horse to a stop, caught sight of Merlin, and smiled thinly. "This is still a bad idea."

"Since when have any of our trips ever been a good idea?" Merlin stepped out of the bushes and motioned the others to follow. "Did you do what I said?"

Arthur nodded. "I told them that I didn't need to take the guard for two thieves. My father thought my abilities were being wasted going after petty criminals, of course."

"What did you tell him?"

"That I was getting restless and wanted something to do. I think the fact that I told him it wasn't likely to be dangerous tipped the scale."

"And me?"

"Said you were coming with me. No-one knows who helped the prisoners escape."

Merlin swung himself up onto his horse and settled in the saddle, finding the reigns. "Alright, Sherlock, you're with me, John, you're with Arthur." He'd impressed onto both of them that Arthur knew absolutely nothing about sorcery or the future, and that he wasn't going to find out any time soon. He trusted both of them, but he thought that John was far more likely to remember instructions. Sherlock had a tendency to wander, especially when he was thinking, and he was almost always thinking. Besides, he and Sherlock needed to go ahead, seeing as they were pretending it was Sherlock who knew the way. The little golden trail stretched ahead of them, shining like the sunlight off Arthur's armour.

Watching Sherlock and John try and get on the horses was intensely amusing, but they managed it with a little help. The sun was rising into the sky. Sherlock sat awkwardly on the horse's rear, his arms tightly clasped around the bottom of Merlin's shirt to prevent himself falling. Arthur and John were a few paces behind, talking softly; Merlin tried to hear what they were saying, and although he couldn't pick it up there didn't seem to be any cause for alarm.

"Not got many horses where you are, then?" Merlin murmured eventually, mostly to distract himself from his own worries.

Sherlock let out a tight hum, and swatted at a fly that shot past Merlin's ear with a panicked buzz. "Far fewer. Not many people ride them."

"How do you get around then?"

"We have…I suppose you could call them carts, but they don't need the horses to pull them."

Merlin laughed. Sherlock's hands clenched around his shirt as the horse swayed in alarm.

"What?" Sherlock hissed, sounding peeved. "What's so funny?"

"When you first got here, you didn't believe in magic. But you have carts that pull themselves." Merlin shrugged.

There was a snuffling sound from behind him, but it took Merlin a moment to work out that Sherlock was giggling.

* * *

"Have you never been on a horse before?"

John resisted the urge to curse, forced himself to remember that this was a prince, that this was bloody _King Arthur _he was sitting behind, and kept his temper. "No."

That seemed to throw Arthur a little; his tone became less patronising, more curious. "Never? Do you not have them?"

John thought for a moment. He could see Merlin and Sherlock laughing ahead of them. "The terrain isn't very suitable for horses. Most people…walk."

"I see." Arthur flipped the reins a little. "You're sitting too far back, by the way – you need to come forward, or you're going to slide off."

Reluctantly, John shuffled forward a couple of inches, keeping his hands hooked into the back of Arthur's belt and trying to ignore the sword, which wasn't as far from his hands as he would have liked. He didn't speak; he understood the delicacy of the situation, and he understood that Merlin was scared. But after lunch, which consisted eating an apple – apparently they didn't have time to stop to eat – on the back of a horse that smelled bad and attracted flies, John couldn't stand the silence any more. In short, he was bored.

Sherlock was rubbing off on him, it seemed.

"So, your father is the king?"

"Yes." Arthur didn't take his eyes off the road; his voice was measured. John found himself wondering if he was cooking inside his armour, but he didn't look uncomfortable. "King Uther Pendragon."

"So you'll be king after…"

"Yes. But not for a long time – my father is healthy, and a good fighter."

John doubted, somewhat, that it would be as long as Arthur thought. It struck him, then, that the man he was sitting behind was going to die. He looked barely older than a boy. And Merlin? What had happened to Merlin?

"How did you come to know Merlin, John?"

"We stayed with him once, in Ealdor," John said, perhaps a little too quickly, knowing he was being tested. Merlin had gone over the pronunciation of Ealdor before they met Arthur, and judging from the way Arthur nodded, he'd said it correctly.

"You travel?"

"Yes."

"Is Sherlock your manservant? Squire?"

John snorted. "Do I look like a knight to you?"

Arthur shrugged. "Some men find it prudent to dress as if they weren't lords when travelling. It can…attract attention."

John resisted the urge to say 'I see you don't mind attracting attention', and instead went for "Why are you helping us?"

"I'm sorry?"

"Why are you helping us to get home?" It had been decided that this would be the story; that Boulby was close to where they lived. John tightened his grip on Arthur's belt as the horse came to a small slope in the path. He didn't know why he was playing with fire; perhaps he had too many romantic views of Arthur built into his head from stories. He seemed far from the Arthur of the tales; from what Merlin had told them, he was moody and sullen and almost stroppy. And John was pushing him. Great idea.

Sherlock had always said he was drawn to danger.

"Because Merlin asked me to."

John blinked; he hadn't expected a reply. "What?"

"He swore to me that you weren't thieves; that you were his friends. I'm doing this because he asked, not because of you." Arthur flicked the reins. "Besides, you can't be any trouble – Merlin's a terrible liar."

John had to bite his lip to stop himself spluttering. Merlin was clever; he let Arthur believe he was an idiot, and all the time, he was there…protecting Arthur, he supposed.

It must hurt him, to pretend.

But Arthur was kind, he realised. He was spoiled and strange, but he cared, even if he wouldn't admit it. Perhaps that made it bearable. Perhaps that was enough.

Not paying attention, he let his hand slip off the belt, and yelped as he burned his fingers on the hot chainmail.

* * *

It got dark early, but the moon was bright and Arthur decided they should keep going for a little. Merlin could tell Sherlock had fallen asleep; his head was leaning against his shoulder, and every time they caught a bump his nose would dig into Merlin's back.

They splashed across a small stream, throwing water up the horse's legs, and Sherlock woke with a jerk and a grunt as the cold water hit their boots. "What?"

"Nothing," Merlin said, smirking. "You fell asleep."

"I didn't."

"You did."

Sherlock sulked. Merlin carried on smirking, glad Sherlock couldn't see it in the darkness, and eased them to the left, following the golden path. It was almost silver in the moonlight, rippling and ghost-like.

A twig cracked. The horse twisted its head, ears swivelling, and came to an abrupt halt. Sherlock was suddenly alert, straightening his back; Merlin could hear him breathing heavily. "What was that?" he hissed.

"Shh." Merlin turned his head and listened. The snapping had come in front of them, but the light showed nothing. Arthur drew up alongside them; both he and John were totally silent. The horses snorted and stamped. Arthur slid from the saddle and drew his sword. Merlin hastily dismounted, pulling Sherlock with him, and John followed their example, scrambling down with a thud. Merlin found and seized a stick – he had a knife, but he felt like something heftier would serve him better. He wasn't planning on getting close.

John had drawn the dagger that Merlin had given to him earlier and was weighing it, looking doubtful. Something touched his neck, and Merlin whipped round, only to see Sherlock had stolen his neckerchief and was winding it between his hands, stretching it taut.

There was no time to ask what they were playing at; no time to wonder if John had ever used a dagger before. Sherlock hadn't even bothered reaching for his; he and John were pressed back to back. Arthur was ahead, sword raised. Merlin hovered in the shadows, waiting. The branch was gritty under his palms.

Nothing happened. For a heartbeat, Merlin thought the twig snapping must have been a fox or rabbit, and, almost despite himself, his arms began to relax.

The bandits burst from the trees like water over a ledge. The horses whinnied in terror, turned and ran into the darkness. There was no time to stop them. Merlin retreated, keeping his branch steady, knowing that Arthur was going to call him a coward when this was over and deciding that he didn't care so long as they made it out alive.

A tree branch snapped under the weight of his will and hurtled down, smashing two bandits to the floor at once.

"On me!" Arthur shouted, charging forward; his sword flickered like dying firelight. Sherlock and John ignored the order – perhaps they didn't even know what it meant – and stayed where they were, still back to back, circling. Waiting.

The first of the bandits slipped past Arthur. For a moment, Merlin jerked forward, ready to intervene, and then the man fell back with John's thrown knife buried in his shoulder. Arthur's sword found a target, someone howled, and one of the bandit's weapons flew out of his grip and smashed into a rock as Merlin moved his gaze towards him.

John reached for the dagger in Sherlock's belt and made feints with it, but his inexperience was obvious; he was a good thrower, but he only had one weapon left, and it was clear he was reluctant to release it. Sherlock was by his side; as Merlin watched he tangled a knife in the neckerchief and held it. John smashed the handle of the knife into the man's head, bringing him down. There was blood in his hair, blood on Sherlock's nose.

Arthur ran into difficulty, going up against three men at once, with a fourth slipping, unnoticed, behind him. Merlin took his eyes off Sherlock and John for a moment, heating the man's sword to molten temperatures even as he swung it. The bandit dropped the weapon with a howl, Arthur span and pushed through the last of his opponents, and Sherlock let out a scream that made Merlin's heart stutter in his chest.

* * *

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**To be continued. **


	8. Chapter 8

**Warnings: Violence, blood.**

* * *

John had been taught to his way around a knife in the army, but there was a difference between learning to use one and actually putting it into practice. He was a far better shot than he was knife-thrower, and the daggers were heavy. He dodged and ducked, and Sherlock helped him when he could, but he knew all they were really doing was retreating in style.

Soon, one of them was going to make a mistake.

As Sherlock dived forward to catch another weapon between the scrap of material, he staggered and, instead of taking the axe at the handle, he caught the blade, which hammered straight down between Sherlock's arms, barely missing his feet. John, seeing his chance, leapt forwards with the dagger, kicking the axe away and forcing Sherlock behind him. Sherlock stumbled against a root and fell. The man attacking them let out a snarl and reached for his knife. There was no circling, no warning, just the flash of steel. John brought the dagger up automatically, but he was to slow, and it was forced out of his hand as the blades clashed together.

The knife came at him again at a speed that boggled him, glinting fiercely, and it would have slid into his ribcage if Sherlock hadn't grabbed his ankle and pulled him down. The blade whistled over his head as he struck the floor. The air left his lungs like rising smoke. The dagger was too far away for him to reach. He had nothing. The man came for him again; John ducked and rolled out of the way, scrabbling for a weapon. He found the axe, but as his hand closed on it the bandit's foot came down on his knuckles, forcing his fingers to spring apart. John yelped, the knife flashed in the moonlight, and then Sherlock was on his feet again; he threw himself at the man's arm, holding it back. The man wrenched round, slamming a fist into Sherlock's chest and sending him staggering; Sherlock lost his grip on the man's wrist. The knife came forward. John was only halfway to his feet, the axe heavy in his fingertips, but there wasn't time, there was no time…

Sherlock caught the blade in his left hand, stopping it a foot from his skin and spraying blood from his palm. The bandit pushed forward; John could see the blade forcing along Sherlock's fingers, slicing in a perfectly straight line. Sherlock was screaming. John swung the axe clumsily, desperately, into the man's shoulder, but either the man was made of iron or he was too intent on Sherlock, because he didn't budge. The axe had bitten into something, and John struggled to work it free, to try for the head. He was sweating. His heart was fluttering like a bird.

The knife finally slid out of Sherlock's grasp, pushing past his bleeding wrists until it was three inches from his chest. Two inches. John let out an involuntary yell, yanking on the axe until his hands slipped and he fell back. One inch.

Arthur came out of nowhere; John didn't even see the sword. One moment, Arthur's arms were raised, and the next, the man's head was separated from his shoulders, the knife dropped, and Sherlock was on his knees, teeth gritted, blood pouring down his shirtfront. John ran to him without thinking, without realising there were still bandits around them, that Arthur had pulled away and carried on fighting, John forgot it all, forgot every detail except the feel of broken twigs under his knees as he knelt, took Sherlock's hands in his, and frantically turned them over.

"Nothing vital severed," he murmured, quickly forcing Sherlock to lie down and lifting his hands above his head. His heart was pounding. With a yell, the last of the bandits crashed to earth. John didn't even flinch. "Hold on."

"I'm fine, John." Sherlock was trembling; his lips were pale and there was blood pattering onto his eyelids.

"Liar." John snatched up the pieces of the neckerchief and hastily bound Sherlock's hands. He doubted it was hygienic, but he didn't have much choice; the amount of blood Sherlock had lost wasn't damaging, but John didn't want it to become any more. He had limited resources, no machines, no tests, not even effective antiseptics or bandaging. The thought crossed across his mind that he should get Sherlock a tetanus shot when they got home.

Sherlock let out a laugh that turned into a squeak as John pulled the bandages tight. "I'll be fine, John."

"I know."

"John. Breathe."

John pursed his lips and puffed out a breath, trying to prove to Sherlock that he was perfectly calm, thank you very much, but his lungs were emptier than he thought and he just ended up coughing.

"I'm fine, John." Sherlock levered himself into a sitting position, cradling his hands in his bloody lap.

"Jesus, Sherlock that was too close."

"I've had worse."

John let out a sigh. "Don't remind me." He quickly reached for Sherlock's hands and lifted them above his head again. "Keep them there."

"My arms hurt."

"Tough."

* * *

Sherlock was sleeping uneasily, but he was sleeping, and John was grateful for that much. It wasn't John's turn on watch – Merlin and Arthur had offered to split the night half and half between themselves – but he couldn't drift off. With a sigh, he picked himself up and headed towards Arthur, who was sitting with his back against a tree, facing into the darkness.

"You should get some rest," Arthur murmured. He had his eyes half closed, but the hand on his sword and the rate of his breathing showed he was very far from dozing. "We have a long ride tomorrow."

John winced at the thought – he was going to be saddle-sore for weeks. "I'm alright."

"And Sherlock?"

"He'll be fine."

"Mm. Good."

John hesitated a moment, resting one hand on his knee and clenching slightly, until he felt his nails dig into his skin through the material. "Thank you. For saving him."

Arthur snorted. "At least I know you weren't lying when you said you weren't knights – you're almost as bad at fighting as Merlin is."

John, reminding himself what Merlin could do, decided not to take offence. "Things are different at home."

"I'm sure they are."

The firelight flickered. A fox barked. Arthur sat, stoic, and John sat, trying to think of a way to truly make him understand what saving Sherlock meant. He couldn't do it. He couldn't talk about death with Arthur, because he knew, vaguely, what his fate was. He couldn't bring himself to look too closely; Arthur had blonde hair and good boots and his eyes were very blue, and he was only a boy. John didn't want to know any more, because he couldn't bear the thought. Silence wrapped around them like a snowdrift.

Arthur went, woke Merlin, and laid down next to the fire, sword still in hand, and Merlin came and took his place. The silence continued; John was entranced by the firelight, watching the smoke curl in circles, haphazard and waving. Like Sherlock's hair on a bad day.

"What are you smiling at?"

John jumped; he hadn't even realised he had been smiling. "Nothing. Just glad that Sherlock…you know."

Merlin nodded. "I'm sorry."

"What for?"

"I shouldn't have taken my eye off you. Arthur can handle himself."

John shook his head. "It's fine. Everyone's fine." He wished he could believe it; believe that the tightness of his guts was just his imagination, that he wouldn't have bad dreams if he fell asleep. "You did enough. With the tree branches." He hesitated. "Is that how you always do it?"

Merlin shrugged, or flinched, John couldn't tell in the firelight. "It's what I'm best at."

"Hasn't Arthur worked it out yet?"

"He's not looking for it. He thinks I'm an idiot."

"He doesn't."

Merlin smiled, tipping his head back until he was resting against the tree-trunk, neck curved, looking up at the stars. "I don't mind. Sometimes, I can't understand how we manage to get by without killing each other, but…he's a good man. At heart." Merlin let out a breath. "Do you think that's enough?"

John looked at the way the firelight cast shadows on Sherlock's face, turning his cheeks to valleys and his eyelashes to rivers, and smiled. "I do."

* * *

The ride was quiet the next day. Sherlock sat with his head leaned against Merlin's shoulder, still dozing, still denying it every time Merlin pointed it out to him. His hands were too sore and too swaddled to get a good hold, and he kept threatening to slide right off the horse, until Merlin loosened his belt to allow him to get a better grip.

The woods gave way to rocks, and then to hills. They made camp. They slept. They moved on. The days slid by, one to two, two to three, almost without Merlin noticing. Sherlock and John didn't speak much, and Arthur spoke even less. It wasn't as if they had nothing to say to each other, it wasn't as if Merlin wasn't still curious. But no-one felt like talking. Even Arthur seemed to sense it; some difference in the air, a difference between Sherlock and John, and Arthur and Merlin.

The trail of light, as they neared their destination, began to grow thinner.

* * *

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**To be continued. **


	9. Chapter 9

"We're here."

Sherlock shifted in the saddle and peered over Merlin's shoulder. His breathing was slightly ragged; John had examined his hands the other day, and shaken his head. They'd found honey to rub on the wounds, but there was a minor infection, and although it wasn't dangerous – yet – it was making Sherlock weak and grumpy. Not that he would admit it. "This looks like the place. From what I remember."

"It'd better be," Merlin muttered, bringing the horse to a stop. "You'll have to tell me what you want me to do."

"We'll need magic."

Merlin glanced behind him; Arthur and John's horse was rapidly catching up. "Let me do the talking."

Arthur finally drew level, wrapping the reins around his hands and frowning. "This is where you live?"

Merlin exchanged a glance with John, who was looking weary and worried, and then shook his head. "No. It's further on. We need to rest here, though."

"But it's only midday." Arthur looked at the sun. "We can get another few hour's riding in before it gets dark."

Merlin caught a glimpse of John gesturing to Sherlock behind Arthur's back, and then Sherlock began to cough, bringing his bandaged hands up his mouth and hacking into them wetly. Merlin understood immediately.

"Sherlock needs to rest," he said, keeping his face straight.

Arthur's face lapsed into a frown. "Are you sure we can't go on?"

"Please." John slid down from the horse, reached for Sherlock and helped him, still coughing, down. Sherlock sank, very convincingly, to the floor. "He needs to rest, or the infection will only get worse."

John's face was compelling, and Sherlock's red cheeks even more so. Arthur sighed. "Alright. We'll stop here. I'll set up camp."

"I can do that," Merlin said, shooting John a look. "John's going to need herbs. And firewood. Why don't the two of you look in those trees?"

Arthur frowned. "Shouldn't John stay here?"

"Do you know how to identify plants?" John gave Arthur a stern glare. "I'm not having you poison him. Merlin can stay with Sherlock; we need to go whilst we still have the light."

Arthur looked like he might have protested, but John solved the situation by storming off into the woods by himself; Merlin knew Arthur, and Arthur wasn't about to let someone he considered such a poor fighter go off on his own. Within a minute, both of them had vanished into the trees.

Sherlock stopped coughing immediately, lowering his hands with a glower. "Don't ever make me do that again."

"_I _didn't make you. John-"

"Be quiet." Sherlock sniffed; he looked haughty, but Merlin got the feeling he was just embarrassed. His cheeks were still red. "We don't have much time."

Merlin took the bag he had retrieved from the dungeon and obediently emptied it out. "What do you need me to do?"

Sherlock reached for the large pan still attached to their horse and began pouring liquid the skins into it – wine, cider and water and dyes mixed together in a strange, brownish pink mix. "This might not work," he muttered. "I'm guessing at the amounts."

"If it doesn't work, Arthur is going to drag you back and have you executed for sorcery."  
Sherlock gave a thin smile. "You can't let him find out you knew about this. You'll need to lie to him, tell him we tricked you."

"Sherlock…"

Sherlock glared at him. "I'm serious. You're important. He's important. I'm not sure how but god knows John is convinced of it."

Merlin blinked, face slackening; his head suddenly felt heavy and confused. "What-"

"Doesn't matter. I need you to do a spell – I need you dig until you find potash."

"I don't know what it looks like."

"Reddish-pink – can you get the image from me again?"

Merlin frowned. "You mean another locator spell, only for an object?"

"If that's how it works."

"I've never done it before."

"Are you willing to try?"

Sherlock looked very intense; if Merlin hadn't known better, he would have said he was gearing up for a spell himself. He was almost feverish.

Merlin nodded.

* * *

"Do you think Sherlock will be alright?" Arthur asked, bending to find more firewood.

John resisted the urge to smirk at the thought of what Sherlock would say to him about this later. "He will. He's strong."

"Can you help him?"

John reached for a herb that looked vaguely interesting and picked it. "If I can find the right ingredients. It might take a while." John, knowing that protesting would be exactly the thing to make Arthur stay with him, let out a sigh. "You don't have to stay. I'll be fine."

Arthur snorted. "You will not. Do you not have swords at home?"

John, insulted but knowing that the definition of 'soldier' was very different for him than it was for Arthur, gave the first answer that popped into his head. "They're banned."  
"_Banned_?"

John had to swallow to stop himself laughing. "I'll tell you about it later."

Arthur was looking at him with a strange mix of sympathy and confusion; John wondered if he'd mistaken his bright-eyed humour for tears. "Sherlock will be fine. He has a physician as a friend, and Merlin has trained with Gaius for years."

"I know." John knelt, found another herb, and added it to the ones in his hand.

"Have you known Sherlock long?"

John almost said 'a couple of years', then remembered their backstory and stopped himself. "Feels like a lifetime. Why?"

"Just wondered."

"What about you and Merlin?" John asked, finding a tree and scrambling into it, trying to make it look like he was examining the leaves. "How long have you known each other?"

"Three years."

"How did you meet?"

"He stopped me doing something stupid."

"Of course he did," John muttered.

"What?"

"I said, that must have been an interesting occasion."

Arthur laughed. "I could have strangled him. I tried to fight him, later on. He has the best luck in the world. But…I'm glad I didn't manage to hurt him, in the end."

"How did he end up being your…" The word servant sounded odd on John's tongue, so he let the sentence trail. If Merlin and Arthur hadn't seemed so happy in each other's company, he might have found it strange from the outset. As it was, they looked more like friends.

"He pulled me out the way of a knife. He's a good man, even if he is an idiot sometimes."

John scrambled down from the tree, tucking leaves into his pocket. "He thinks you're a good man, too."

Arthur blinked. "He said that?"

"Don't tell him I told you."

For a moment, Arthur just looked confused. And then he smiled. John pretended he hadn't noticed.

"We need to keep looking."

"Don't you have everything yet?"

John wondered how long exactly it would take to mine minerals by magic instead of drills, and swallowed. Like it or not, he had to give Sherlock and Merlin as long as he possibly could, just to make sure. "Not yet."

Arthur sighed. "Then I'm going back. I want to get the fire started early – there's nothing in these woods, or we would have attracted its attention by now."

John felt his cheeks drain a little as he stood, still up to his arms, in a bramble patch – the things he did for Sherlock. "Are you sure?"

"You'll be fine." Arthur smiled. "We're not far out; if you run into trouble, just shout."

"Alright," John replied, forcing himself to wait until Arthur had dodged out of sight behind the trees. Sherlock and Merlin had no doubt expected more time than this; if Arthur came back and saw what they were doing…

Arthur would be walking; he had the firewood and his armour to deal with. If John could get around him, he could get their first.

He dropped the bundle of useless herbs, got to his feet, and began to sprint.

* * *

When Merlin had finally raised a small, round piece of rock no larger than a raspberry out of the ground, he frowned. It was the colour of a worm, ugly and jagged.

"This is it?" he muttered. "This is what we had to come here for?"

Sherlock plucked the rock out of his hand. "This is it." He scowled. "There isn't much of it."

"I had to lift it miles out of the earth," Merlin snapped. "It's heavy when you have to hold it for five minutes."

Sherlock sighed. "It'll do; if this is going to work, then it's going to work. The size of the thing isn't going to make any difference." Sherlock had finally finished smashing at the silver fork with a rock. He took one of the severed prongs and dropped it into the pan. "This is far more silver than we need, and we don't have enough wine. Either the elements will come together enough for this to work, or we'll have to do it exactly."

"Is that possible?"

"Only if I can invent electricity and get this potash into potassium."

"Invent what?"

"Nothing." Sherlock scrubbed a hand over his face leaving a streak of mud over his eye from the bandages. His cheeks were still red. Perhaps there was more to the infection than Merlin had thought. "Everything's in there now, apart from the potash."

Merlin leaned over to drop the rock into the pan, but Sherlock caught his wrist.

"Not yet! We need to do it at the same time – the same time as your moment. Did you work out what it was?"

Merlin felt his armpits sting a little. Doing it the first time had been stupid, and it was downright dangerous now.

"Yes. But I need Arthur to be there. It was…different magic. Involuntary."

Sherlock pressed his hands to face and closed his eyes. "Wonderful."

"I can do it."

"You'd better." Sherlock raised his head and smiled. He looked exhausted. "Thank you."

Merlin shrugged. "You don't belong here; I wouldn't belong in your time. If it had been the other way round, you would have helped me."

Sherlock opened his mouth to reply, and then the sound of footsteps burst into their hearing, humming like a swarm of bees. Merlin whipped his head around, panicking for a moment, until he saw John, pink-faced and out of breath, speeding towards them.

"Thank god," John murmured, coming to a halt with his hands over his knees. "He's coming back – I…I…"

"Had to run?" Sherlock was smiling, but the lines of his face were taut. He extended a hand to John, the ball of potash rocking in his palm. "We're ready."

Merlin got to his feet. "I'll meet Arthur – you stay here. When you hear the signal, put the potash in."

"What's the signal?"

"Arthur laughing."

Sherlock raised an eyebrow. John didn't look surprised, but he might just have been too out of breath. "Merlin?"

"Yes?"

"Be careful."

Merlin smiled. "I always am." He hesitated a moment, but he had to know. He had to hear it in numbers and words, not vague concepts. "What was the date, exactly, when you left?"

"Fourteenth of October, 2010," John said, and Merlin couldn't stop himself clapping a hand to his mouth. John frowned. "What? Why?"

"No reason," Merlin said, still resisting the urge to laugh out of sheer amazement. "It's just…wonderful."

Sherlock smiled. "Go intercept Arthur. We'll listen for the signal."

Merlin hesitated a moment. "I suppose I should say goodbye."

For a moment, Merlin thought he saw sadness flicker across John's face, but then he nodded. "Goodbye. Be careful."

"You already said that."

"I mean it."

Merlin gave him a brief nod, turned on his heel, and left.

As soon as Merlin had gone, John crouched by Sherlock's side and took the potash from him. "I was the one who knocked it in last time," he murmured. "I probably have to do it now."

Sherlock nodded. The two of them crouched, breath mingling in the cold air – they both really needed to brush their teeth – waiting. Sherlock reached up and started unpicking one of the bandages. John slapped his hand. "Don't do that, you'll make it worse."

"You need to take my hand."

"What?"

"When it happened, I'd tried to stop you. I was holding your hand – I don't want only one of us to get sent back now."

The thought turned John's spine to ice. "Definitely not."

Sherlock peeled off the last of the bandage and threw it away, then held out his hand. "Here."

"Does it matter which hand?"

"Can you remember which it was last time?"

John thought for a moment, then shook his head. "No."

"Then we'll have to hope it works anyway."

John nodded, and then put his right hand over Sherlock's, keeping his left tightly curled around the potash. There was a tiny hole in the earth, he realised, a narrow and vertical tunnel, where Merlin must have brought it up. Sherlock's cuts were sticky under his palm.

"Ready?"

Sherlock squeezed his hand.

* * *

**Thanks for reading, feedback welcome!**

**To be continued. **


	10. Chapter 10

Arthur came from the trees slowly, carrying the firewood all wrong – of course he was, Merlin thought, smiling. "Here," he called, grabbing for a stick before it fell. "Let me help you."

"I'm fine, Merlin," Arthur said, almost pouting, but he seemed in a good mood. Briefly, Merlin wondered what John had said to him in the forest. If it had been anything at all. "How is Sherlock?"

"John thinks he can help him. They just need some space."

"Space?"

Merlin waved a hand. "John's the physician." He led Arthur as near to the horses as he dared – near enough for Sherlock and John to hear them, but not so close so that Arthur could see what they were really mixing in the pan. "We'll make the fire here, they can join us afterwards."

"John got back fast." Arthur said, looking confused, but he set the wood down. Merlin swallowed; his throat was very dry. In that instant, every idea he'd had, everything that would make Arthur laugh, vanished from his head. He had no jokes, no reason to joke. How did he makeArthur laugh?

Usually, it just happened. He didn't _try_ to do it.

"Are you alright?" Arthur asked, frowning.

"Fine. Yes." Merlin fumbled the sticks he was holding. "Fine."

"Are you-"

"I'm sure." Merlin got to his feet, intending, in a desperate attempt to hide his rapidly reddening face, to reach for the saddle bags, but his foot caught a rut in the earth and he fell backwards with a yelp. Arthur reached for him, grabbed the front of his shirt, and held him, suspended above the ground, wide-eyed, heart thumping.

For a moment, Arthur just looked surprised. And then he smirked. "You should see your face."

Merlin laughed; not because he had to, not because he knew it would make Arthur do the same, but because he couldn't help himself. In the moment Arthur hauled him back upright, Merlin had no idea what he was doing, but he laughed anyway. And so did Arthur, tipping his head back a little, eyes half-closed. The light glinted off his armour. Merlin, only semi-conscious of what he was doing, felt his fingers spark.

By the time they broke of laughing, Arthur's face was red and his hair loose. But, as soon as he raised his head, his smile suddenly dropped into a frown. For a moment Merlin panicked, but then Arthur stepped past him, leaning over the horse and staring.

"Where did they go?"

Where Sherlock and John had just been, there was only the pan, still smoking.

* * *

John came to with a jolt to find himself sprawled inelegantly on the floor of the kitchen – he never thought he would have said that he missed linoleum, and yet, here he was – and frowned. He could smell burning bananas. For a moment, he assumed it was dream, until he saw Sherlock, slumped in his chair with his head rested on the table and his arms by his sides. One hand was still in dirty bandages. The other was red-raw and sticky.

"Sherlock," John hissed, getting to his feet and staggering. His head felt as if it had been stuffed with bees; his ears were throbbing angrily. He'd felt like this last time though, and it had worn off. It wasn't important. "Sherlock," he repeated, putting a hand on Sherlock's shoulder and shaking it.

Sherlock suddenly jerked his head up, neck cracking. "Did it work?" he slurred, bringing a hand up to his face and removing the piece of paper that had stuck to his cheek.

"Yes, thank god, yes it did. Get up," John said, offering him a hand. "What day is it? Mrs Hudson is going to be worried sick about us…"

Sherlock scrabbled for his phone, wincing as his cuts opened and started smearing blood on the keys, and frowned. "It's still the fourteenth."

"What?"

Sherlock held the phone out. John stared, and looked down at his watch. It was working again; it was barely five minutes from the moment they'd left.

"That's not possible."

Sherlock raised an eyebrow. John pressed a hand to his forehead, trying to stave off the massive headache he knew he would be having very soon.

"We need to get you to a hospital before that infection spreads."

Sherlock looked down at his hands, which were dripping onto the table, and, for the first time in his life, didn't argue.

* * *

"What's that?" Sherlock asked, popping an antibiotic out of its case and swallowing it down with water. Life had returned to normal very quickly - their visit to the hospital had been hasty and full of lies, and the grim sight of A&E late in the evening had been enough to ground anyone in harsh reality.

Neither of them had tried to explain away what had happened, or say it wasn't real. There was no point in pretending.

John set the book down on the table – now completely clear of anything photograph or potassium related – and opened it up. "Book of Arthurian legends. Found it in the library."

Sherlock leaned over his shoulder. "Interesting."

"None of it's very accurate," John added. "The tales contradict each other, one book has a slightly different version to another, the internet is full god-knows how many tales." He turned a page. "Most of them agree on one thing, though."

"Camlann."

John jerked his head up. Sherlock shrugged.

"I've been reading too."

With a sigh, John flipped another page, but didn't look at it. "They were so young, Sherlock."

"No-one knows for certain when it happened." Sherlock's finger came down and stabbed at an illustration. "I mean, Merlin's looking rather older there than I remember him."

John laughed, despite himself.

* * *

The postcard came a week after the fourteenth. John was making tea. Sherlock was sitting in the lounge, but John didn't bother asking him to get the post when he heard the letterbox, because he knew Sherlock would only snap at him and tell him that he was 'thinking'.

Two bills, a free magazine, and a postcard. John went for the postcard first, curious; he didn't know anyone currently on holiday.

There was a picture of a wide river and the words 'Visit Usk' in small, red print. John frowned, and turned it over. There was nothing written on the other side; nothing except the word 'potash' and a signature that it took him a moment to decipher.

"He's still alive!" John shouted, forcing Sherlock out of his chair with a jerk.

"What?" Sherlock got to his feet, looking grumpy. "You interrupted my-"

"Shut up and look."

Sherlock took the postcard, read the writing, and turned it back to the photo. "The Usk is a river near Caerleon."

"One of the possible locations of Camelot," John finished, blowing out a breath. "He's still alive, Sherlock, how can he still be alive?"

Sherlock stroked a thumb over the 'M' of the signature, frowning. "I suppose he was…well, him."

"Magic."

Sherlock gave a curt nod, went to the fireplace, and propped the postcard up behind the skull.

"But why hasn't he come and found us?" John said, following Sherlock into the kitchen and reaching for the now-boiled kettle. "All this time…"

"Maybe…" Sherlock found a chair and sat on it heavily. "Maybe he's not ready."

John hesitated a moment, teabag slipping on the spoon. "And when he is?"

Sherlock shrugged. "Who knows?"

* * *

**Well, there you have it! I found this one pretty tricky to do, and I'm still not entirely happy, but I really hope you enjoyed it all the same. Thanks to everyone who's left encouragement, you're all lovely! **

**The end. **


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